Blender Best Car Crash Problem
After a day of research, I found out some of the answers and I am going to answer to my own questions

Rotating wheels when car is accelerating &lt;- for the wheels, add drivers to an empty axis, then move the axis, the wheels should rotate (tested out, it works)
Car skidding, thus front wheels turn left or right (imagine the driver trying to take but control of the vehicle and end up drifting) &lt;- rotate the front wheels on the z-axis via the empty axis in between key frames (haven't test it out, still figuring out how to add drivers on the z-axis)
Car hit an obstacle on the road at high speed and fly off course &lt;- parent the empty axis to a cube, the cube is in the shape of the car, wrapping around the car (tested out. tried hitting the cube together with the car to a stationary pole straight on. not sure why, but upon impact, the pole was absorbed into the cube and car and stayed inside them. the cube and car then kept shaking while the pole is inside of them)
Car Crashing (glass shattered, metal part tented) &lt;- upon impact, manually dent the car and use key shape key function. not sure about shattered glass. perhaps separate the glass parts from the car at the key frame upon impact? I know about cell fracture but not unsure how to make the glass break upon impact. the windscreens are tempered glass, depending on impact, it should either crack or break. (tested out only on denting the car, it works)

It seems like there's no way to add a rigid body onto the car. That is why I have to parent the car to the cube (that is in the shape of the car). Because every time I add a rigid body to the car, those parts that have a rigid body added will just drop onto the ground all over the place. Please let me know if there's a way around it.
Hope someone will be able to help, especially with the cracking of tempered glass and glass shattering part. Windscreen should crack while side and rear windows should shatter. Because every time I try to add a rigid body to the car, everything just fall apart. I will update again if I can find out more.
Have fun crashing.
John